<script setup>
const props = defineProps({
  modelValue: {
    type: Number,
    required: true
  }
})
const emits = defineEmits(['update:modelValue'])
const btnClick = () => {
  emits('update:modelValue', props.modelValue - 5)
}
</script>

<template>
  <div class="son-page">
    son---{{ modelValue }}
    <br />
    <button @click="btnClick">修改modelValue</button>
  </div>
</template>

<style scoped>
.son-page {
  width: 300px;
  height: 300px;
  border: 5px solid red;
}
</style>
